My father told me tonight that scientists are afraid to admit that there is a god.

This came up because he was afraid to try kangaroo meat. He said they are rodents and I told him they are actually marsupials, but then I made a joke about him starting to believe evolution.

He had apparently had a bad day today and it made him very upset even though I was just trying to be funny.

I partly didn't think there would be a problem with it because I know in the past he has conceded that many things about evolution are hard to deny.

We also had a short discussion a few days ago about the existence of god, and while it ended abruptly, it went very well (nobody got angry) and he got beaten pretty soundly, over which I'm sure he has been agonizing ever since. We are both very alike and overly analytical lol.

Tonight he ended up saying things like, "that car and this car may have a similar build but that doesn't mean they evolved from each other, but you can't deny they had a creator."

I wish I was more knowledgeable regarding all things science, but all I really have is a basic and sometimes shaky understanding of evolution, the universe, etc.

I could, however, see that his knowledge of the subject isn't all that more advanced than mine (which is saying a lot because he studies and retains information better than I do, and he understands and loves science for the most part)

What would you wise people have said in response, and where would you send him (and me!) to find information that is somewhat easy to understand.

I recall a website being talked about, "talkorigins" or something? Is that the name of it?

Thanks for your help, all!

Logged

"i dont delete them becAUSE IT PROVES ME WRONG I DELETE THEM BECAUSE IT MAKES U LOOK LIKE AN DIOT AND? IM TRYING TO HELP YOU,THE ONLY THING U PROVED IS THAT UR GOING TO HELL " - A Christian on youtube who kept deleting my comments during a debate.

This, http://www.transitionalfossils.com/ is a listing of well-evidenced fossil lineages, as well as some clarification of what exactly is meant by "transitional" in terms of fossils and evolution.

As to what I would have said in that situation, it probably would have been something like: "We know that humans design and make cars, we can go and see for ourselves people doing just that at every stage in the process. Aside from humans using selective breeding and direct genetic alteration, we don't see any deliberate agency changing living things. Instead, we see undirected processes like mutation and natural selection effecting changes in the short and long term."

Glad that you and your dad can have civil discussions about something he finds controversial. Hopefully he's willing to consider changing his views at least somewhat; many theists have no problem accepting evolution. Best of luck to you both!

Logged

Live a good life... If there are no gods, then you will be gone, but will have lived a noble life that will live on in the memories of your loved ones. I am not afraid.--Marcus Aurelius

Tonight he ended up saying things like, "that car and this car may have a similar build but that doesn't mean they evolved from each other, but you can't deny they had a creator."

Cars have to have a designer and also a manufacturer because they don't make offspring either sexually or by vegetative reproduction. Variation in new car models has to be deliberately conceptualised, developed, and produced by a "creator" such as Ford or Ferrari (not God btw).

In living things the source of variation is not deliberate - it simply arises through a natural process where random mutations (from molecular damage and mistakes in reproduction) get into the DNA code. Most mutations have a negative effect (often lethal), some are neutral, and a tiny few improve adaptation (or sexiness in some cases). No "creator" is required, nor does it fit with the idea of a God-like creator because so much of the variation is lethal, and so many species go extinct because their "design" could not cope with changes in the environment. It's reasonable to expect that a God-like creator would get most things right, not most things wrong

In my experience scientists are not afraid of God. Some are afraid of the broader meaning and consequences of scientific discoveries. When science can explain something that religion previously told us was due to God's "hand" e.g. lightning, diseases, earthquakes etc then the discoveries undermine faith and the authority of religions that previously told us they had the correct explanations.

The truth is that religion is afraid of science - and for good reason because religion is being forced to concede that its scriptures are wrong on just about every subject where science bothers to shine its light. The earth isn't the centre of the universe, donkeys don't talk, there are no archaeological records of the Exodus, the dispersion of animal species does not fit with Noah's Ark story.

Now while I was typing this answer I see Wright has covered much of the same ground as me, and he has given you excellent links.I also suggest looking at the inspirational new scientific work showcased by a site such as:http://www.newscientist.com/

Just say Dad, I don't believe in devils and angels and all that jazz. But I do believe in love. Let's just agree on that and let me know if you're ever struggling with your faith, I am only to happy to offer a helping hand. Think of it as killing the debate with kindness.

Why waste time on an argument that thousands before you have. Makes no sense. :-)

Just say Dad, I don't believe in devils and angels and all that jazz. But I do believe in love. Let's just agree on that and let me know if you're ever struggling with your faith, I am only to happy to offer a helping hand. Think of it as killing the debate with kindness.

Actually, William, you're incorrect about mutations. Most are neutral and thus have no real effect on the organism in question. Only a minority have a net positive or negative effect. For a mutation to have an effect at all, it has to happen in a part of DNA which is expressed. But most DNA is never expressed, to the best of my knowledge.

Nonetheless, this does not contradict your point about the difference between cars and people. Cars do not have a mechanism which allows them to reproduce, or to vary themselves for that matter. Thus, the only explanation for the existence of a car is that someone created it. But since humans do have a inborn reproductive capacity that also allows for significant variation, there is no real comparison between a car and a person in that respect.

Comparing something purely mechanical (including electronic) with life and then drawing conclusions requires ignoring certain realities. The reason cars have a designer is that there is no mechanism in nature, at least that we have here on earth, to create functional machines that are otherwise inert. That is, not alive. Nature can't create them, nature can't reproduce them. Living things, on the other hand, do have the capability of evolving and reproducing, and therefore they are very different.

And our functionality (or disfunctionality, depending on who is measuring what) is a byproduct of past evolution, not design. We are an end-product (well, not really, we are an inbetween product between early mammals and the mammals to come over the next few million or billion years), and whatever characteristics we have just happen to be, because that is where we are on the evolutionary ladder, not because some fantastic being molded us out of dirt or ribs a few millennia ago.

Acknowledging that there are many scientists who believe in a god, those that do not can hardly hate god, being as he doesn't exist. If any of them are like me, they are none too excited about dark-aged thinking and voluntary ignorance, as exhibited by all those religions that try to spoil the view of the universe. But there is no hate involved, vis–à–vis the god idea. That would be a waste of time.

The gathering of more accurate knowledge will always challenge preconceived ideas. Which is usually uncomfortable for people. Especially those who prefer that their world be set in stone and simple. Should you choose to continue challenging your father, blue_spral, you may occasionally push him to his limits. You need to be sure you want to do that with someone you love, and to be prepared for less than optimal consequences. Consider broaching the subject of god in little bits and pieces, rather than trying to do it all in one fell swoop.

Because you're probably too young to know what a fell swoop is. Which may mean that your youth has you placing too much importance on being right, which isn't always absolutely necessary when you are with someone you love.

Logged

It isn't true that non-existent gods can't do anything. For instance, they were able to make me into an atheist.

Actually, William, you're incorrect about mutations. Most are neutral ...

Thanks for that Jaimehlers, I do love being wrong sometimes because it makes me learn In this case I submit we may both be right My thinking is this: If a deleterious mutation results in cell death (germ cell line), or failure of fertilization, or spontaneous abortion, or death before reproductive age ... how do we detect and measure that particular mutation? It expunged itself before it could be counted. On the other hand, neutral mutations we can detect aplenty - simply because they survive.

For a mutation to have an effect at all, it has to happen in a part of DNA which is expressed. But most DNA is never expressed, to the best of my knowledge.

Yes the DNA that is "expressed" is fairly critical - even though there is some codon redundancy that can tolerate a few hits without altering the expressed product. (And this is of great help in measuring rates of mutation and the evolutionary distance between species.)However, the idea that "most DNA is never expressed" is now being seen in a very different light. Although much of this DNA is not transcribed, it still plays a vital role in the regulation of gene expression and appears to be highly conserved (so the integrity of its encoded info must be critical):

Quote

However, many types of noncoding DNA sequences do have important biological functions, including the transcriptional and translational regulation of protein-coding sequences. Other noncoding sequences have likely, but as-yet undetermined, functions. (This is inferred from high levels of homology and conservation seen in sequences that do not encode proteins but, nonetheless, appear to be under heavy selective pressure.)

http://en.wikipedia.org/wiki/Noncoding_DNASo it appears the DNA that is "never expressed" is indeed used in the expression machinery and as such is vulnerable to mutations that can disrupt cell functions in lethal ways.

I used to have a response to the watchmaker argument but I don't remember what it was lol.

I ended up having an IM conversation with my mom later in the evening, where I addressed the idea of scientists being afraid of god. She argued that she knows scientists that believe in god, etc. etc. and by the end of the conversation she changed the subject in confusion.

I'm sure she discussed that conversation with my dad so I got to get some points in. But it's likely to come up again

« Last Edit: August 23, 2013, 06:17:54 PM by blue_spiral »

Logged

"i dont delete them becAUSE IT PROVES ME WRONG I DELETE THEM BECAUSE IT MAKES U LOOK LIKE AN DIOT AND? IM TRYING TO HELP YOU,THE ONLY THING U PROVED IS THAT UR GOING TO HELL " - A Christian on youtube who kept deleting my comments during a debate.

When humans design things, we use top-down, bottom-up, and iterate design:

Top-down design: I want to make something that drives. I'll need wheels, somewhere to sit, a way to steer, etc. *Makes car*

Bottom-up design: I have a car. I think it would be better with/without a horn. *Adds/removes horn*

Iterative design: I invented a touch screen. I'm going to put it on the car radio. And this phone. And this tv. And this oven. And this GPS. Let's just go ahead and roll it out to all electronics.

Evolution is a bottom-up mechanism. Every organism must either mutate its own traits or inherit it from an ancestor. If sharks develop cartilage that is resistant to cancer, it does not get rolled out to humans. Animal eyes do not get rolled out to squids; they have to develop their own independently. Creatures do not spring into existence out of nowhere; they must come from a prior species.

So, if this was a world of creation, we would expect to see evidence of top-down design, bottom-up design, and iterative design. If this was a world produced by evolution, we would only expect to see evidence of bottom-up development.

Bottom-up design: I have a car. I think it would be better with/without a horn. *Adds/removes horn*

Mutation and natural selection have no intent - they're not planning to go somewhere in particular.

Niches open up in nature - variation happens and eventually one of your "bottom up" variants finds itself in a happier fit within the niche, and passes on its genes to progeny that prosper in that niche. Then eventually further variants upon that group find themselves in an even better fit with the resources and threats of the niche, and so on for generations until they can no longer interbreed with their ancestral strains. It's a process that never stops, never arrives at a final intended destination, and has no idea what's coming next.

Blue_spiral, since others (including a god-believer) have answered your questions regarding evolution, I am curious about the explanation to something in your post...in the same spirit as the title of this thread:

Actually, William, note that when he gave that example, he was only talking about when humans designed things (which means it would include intent).

This time you are right and I'm wrong. Sorry Mooby. And thanks Jaimehlers.

No worries. I should have been more clear: design can be a bottom-up process, and evolution can be a bottom-up process, but the former has intent while the latter doesn't. In our observations it can be difficult to tell exactly the difference between bottom-up design and bottom-up evolution, but the absence of evidence of other types of design that we would expect would be used by a competent, efficient designer leads much lower support to a design process.

The answer to this question is the same as the one to the question "Why are atheists afraid of/angry at god?", and that answer is: They aren't.

Logged

The truth is absolute. Life forms are specks of specks (...) of specks of dust in the universe.Why settle for normal, when you can be so much more? Why settle for something, when you can have everything?We choose our own gods.

Yes, Talk Origins Archives is a extremely informative site. Explore around there, and gain understanding of macroevolution, microevolution and each of their components until you are able to explain it. Once you can explain it (even to yourself), you know you are ready to explain it to someone else. It is so awesome you can have a civil discussion on such a tender subject of conflicting with ones faith. Find things in science that he can relate to, that shows science working in the same manner when it comes to evolution. Good Luck !!!

Logged

This planet and universe puts me in awe everyday. Its not that I want to live forever, just long enough to learn everything =) ~This is me

I know a Physicist who's a Roman Catholic. There are many scientists who believe in a god/s. Being a scientist doesn't make one an automatic atheist.

-Nam

I personally know two Mormon scientists, off the top of my head.

We were discussing the topic of science and she was trying to make the argument that science supports god claims with the fact that scientists can be religious.

Logged

"i dont delete them becAUSE IT PROVES ME WRONG I DELETE THEM BECAUSE IT MAKES U LOOK LIKE AN DIOT AND? IM TRYING TO HELP YOU,THE ONLY THING U PROVED IS THAT UR GOING TO HELL " - A Christian on youtube who kept deleting my comments during a debate.

Atheists are not obliged to explain the origin or the diversity of life. If you don't feel like defending the Theory of Evolution just say "I don't know" and just because you think you do, doesn't mean you are right. There are many things we don't know and many things in the past, such as gravity, have been mysterious until a natural explanation was eventually found. Just because you can't explain something doesn't give the other person a license to fill the gap with a supernatural explanation. (Argument From Ignorance - a classic fallacy)

IMO it is usually not worth arguing Evolution with most believers, not on an individual leve. You will have to struggle against their mangled misconception of the theory, it's counter intuitive and defies "common sense" and you have to know quite a bit to be able to answer all the "facts" they will find on the Creationist sites.

Cars themselves do not reproduce. They are perhaps analogous to a seedless fruit. However, mechanical designs and aesthetic styles do show clear lineages and there is a selection process at work. Engineers and designers build on previous successes and abandon failures. A careful examination of the history of the automobile will likely show a marked pattern of experimentation, selection and inheritance but at a more abstract level than is found in living creatures.

Most mutations have a negative effect (often lethal), some are neutral, and a tiny few improve adaptation (or sexiness in some cases).

You never did get around to showing the evidence to support your assertion that most mutations have negative effects (either harmful or lethal). Given that the discussion with DT went off the rails around that time, this isn't surprising. So I figure this topic might be better for continuing that discussion.

What you showed is that people in Ukraine, after the Chernobyl disaster, have an unsustainably high rate of lethal and harmful mutations - which, given the natural population decrease there, argues against the number of lethal mutations being anywhere near as high in a healthy population of humans. Indeed, your statement above is almost a direct quote of the typical creationist argument regarding mutations. "Most all mutations are detrimental, a few are neutral, and extremely few if any are clearly beneficial."

Now, the mere fact that creationists repeat an argument does not make it wrong. What makes it wrong is that the argument for a high number of deleterious mutations is not supported by actual scientific studies regarding genetic mutations.

http://www.genetics.org/content/156/1/297.full - "The average mutation rate was estimated to be ~2.5 × 10?8 mutations per nucleotide site or 175 mutations per diploid genome per generation" and "Using conservative calculations of the proportion of the genome subject to purifying selection, we estimate that the genomic deleterious mutation rate (U) is at least 3." Now, granted, they are using a conservative estimate, which means it could be (and likely is) higher, but...3/175 is less than 2%. Tripling that rate for the sake of argument results in a 5% rate of deleterious mutations, which is not nearly high enough to justify your (or creationists') argument that most mutations have a negative effect.

http://www.webpages.uidaho.edu/newton/math501/fa2007/adaptivemutrate_science07.pdf - "Given the estimates for the overall mutation rate in E. coli (30) and its genomic deleteriousmutation rate (1), our estimate of Ua implies that 1 in 150 newly arising mutations is beneficial and that 1 in 10 fitness-affecting mutations increases the fitness of the individual carrying it." What this says is that the rate of deleterious mutations in E.coli is 1/30, and the rate of beneficial mutations is 1/150, which accounts for 6/150 mutations. The rest, therefore, must be neutral.

The implications are clear. The mutation rate follows a bell curve[1] rather than an asymptomatic one[2], at least under normal circumstances on Earth (meaning, there are no environmental factors which push the mutation rate up). Furthermore, even if the mutation rate is increased due to environmental factors (such as the ones that hold in Ukraine, today), there is no reason to expect that the proportion of beneficial/neutral/deleterious mutations would change - only the total mutation rate. This still leads to a higher number of deleterious mutations, and since a single lethal mutation overrides all other mutations in terms of viability...

By the way, I do understand the point you were trying to make about lethal mutations removing themselves from the gene pool. The problem is that new mutations always crop up, in every generation, and some of those will be lethal. While it's certainly true that lethal mutations aren't conserved, that means nothing as far as new lethal mutations are concerned, and all it takes is one. My point is that you shouldn't conclude that since lethal mutations aren't conserved, then it doesn't matter how many there are. Because as you showed with the post-Chernobyl Ukranians, a high enough number of lethal mutations threatens the long-term survival of a species.

..... a high enough number of lethal mutations threatens the long-term survival of a species.

I remember reading an interesting article on this subject. Based on mathematical simulations of evolution, it argued that life is only possible within a rather narrow temperature change. Too cool and information is preserved too well and the population cannot produce mutations fast enough to adapt to change, too hot and mutations occur so rapidly that the fertility rate plummets due to lethal mutations.

Logged

I was a hidden treasure and I longed to be known. So I created the Creation so that I may be known. hadith qudsi

...gain understanding of macroevolution, microevolution and each of their components until you are able to explain it.

TiM, in a nutshell can you describe any differences between macroevolution and microevolution? I have trouble with that one myself.

That's like asking "what's the difference between a cent and a euro?" Lots of cents make a euro, only difference with evolution is that with money, you know ahead of time when you'll get a euro. In evolution, it might be 100 generations or 1000 or more still.

btw, I once saw this documentary that did say cars could reproduce on their own ... no, wait, that might have been one of my son's Disney movies

“Why are scientists afraid of God?” is one of those silly questions that people ask if they have never bothered thinking about what it is that they have just said.

Assume that you are a scientist, someone at the cutting edge of discovery, and there is a god of some sort. What is it that you are doing that might upset that god? There are priests and apologists who seek to discover the nature of this god and speculate on his nature – they seem to think that this god approves of them. You are doing the same thing, aren’t you?

You look back in history and, for the previous 200 years, no scientist has been attacked by any god. Why should you worry? What is it that scientists do that would upset a god?

Your discoveries and those of your colleagues will lead to the conclusion that there probably is a god, there probably is a god but it isn’t the one you thought it was, or that there probably isn’t one. Nobody has ever been struck down by a god for any of these conclusions. Even the Bible contains no reference to being struck down by gods for a lack of belief – apparently the Judeo-Christian god inspires men to do his dirty work – he himself remains aloof from this.

Could it be that the scientists secretly know that they are cheating in some way? If so, why do their discoveries work? If they work and there is a god, surely, that they work is a sign of that god’s approval?

In short, can someone explain why a scientist should be afraid of a god?

Part 2.

ID is simply garbage. It has no choice but to admit evolution of some sort. I am assuming that they are happy with e.g. the cat family which consists of everything from lions to domestic cats. However, if any of these interbreed, the offspring is infertile, so how come the species as a whole made it through time? There must have been every species to start with and yet evolution is visible within the scientific record.

And this is where their trouble arises:

Imagine something that does have a designer -> a car.

What they will not accept is that, in the case of the car: In The Beginning there were ores and then there was wood and then there was fire and then there were round logs and then there were wheels and then there were metals and then there was steam and then there was oil and then there was electricity and then we had a car and then there were electrical valves and then there were transistors and thenthere were CPUs and these were put in cars.

So everything goes back to what was chemical molecules.

Their question is, “How did something as complex as an engine management CPU come into existence? It is irreducibly complex! Do you just think it evolved?!!! Why would it evolve if there was no car to fit it? Obviously it was created!!!111!! Jesus invented the car!”

The problem they have is that they start at a point at which a complex creature is already there and complex, and ask how a complex organ “just appeared” or why a particular adaptation exists when that adaptation has only one function which is associated with that animal’s ability to live.

And all they need do is ask, “What came before this?”

Species: We can show that hippos are related to whales and dolphins, whereas the hyrax (Le:11:5) is related to the elephant (behemoth.) So here we have different species coming from one. (Checkmate, godbotherers!)

Does anyone see the similarity between IDers’ arguments and maintaining that the earth is flat?</rant>

Logged

Nobody says “There are many things that we thought were natural processes, but now know that a god did them.”

You never did get around to showing the evidence to support your assertion that most mutations have negative effects (either harmful or lethal).

Jaimehlers , actually I did ... quite substantially more than two weeks ago, and under some pressure being away OS with difficult internet access. But I can see that the "Impossibility Argument" was a hectic thread, so I completely understand that you missed my posts, and thus never did me the courtesy of a response.

BTW I've had a careful look at the references you've linked here in this thread. Perhaps you should too Hint - think about:

By the way, I do understand the point you were trying to make about lethal mutations removing themselves from the gene pool.

Test that insight I gave you against the references you quoted

Now I'm busy catching up with work and priorities after a month away from home. I hope to respond to your post here in detail on the weekend. Although you might decide to retract some parts of it in the meantime

So I figure this topic might be better for continuing that discussion.

Okay, fair enough, I know it's very hard to read everything posted for your particular attention on WWGHA, so here is a repeat of my careful responses to you that you didn't see and so didn't reply to:

Oh, you're just talking about human reproduction? Next time, specify that. I was talking about animal reproduction in general and the effects on generational levels of organisms....

Quick reply. Jaime I don't need to restrict myself to human reproduction to show that your generalisations about "fecundity" are simplistic and don't necessarily hold up in nature. Contrary to your statement:

Actually, it is a response to environmental pressures. The fecundity of a species tends to change depending on the kind of pressure a species faces; if food is short, organisms become less fecund, whereas if predators or disease hit a species hard, they become more fecund.

Predation on birds - very common finding that realised fecundity drops - another example of the exact opposite to what you said It's because breeding activities are disrupted during nest defence, and eggs and chicks are taken. The impacts carry on for many generations - basically for as long as the predation pressure remains. Relief only comes if the birds depart the scene to nest in an entirely different location or find nest sites out of reach of the predators, or if the predator numbers decline or they move on to happier hunting grounds.

Anyway, I'm still conceding that point, because there are mechanisms that work as you said they do

The Chernobyl disaster was only a single generation ago, though - what was it, 1986? There simply hasn't been time for the increased likelihood of offspring deaths to have the effects I predicted on fecundity. Give it a generation or two - ....

This is also not quite right. Humans don't reproduce in generational batches. There is a continual procession of people reaching reproductive age since Chernobyl. Many of those reaching peak reproductive age are already now "second generation". Yet the local decline in realised fecundity continues. It is not local fecundity that will "respond". It is the purging effects of negative selection coupled with migration from other areas that will eventually make it appear like a fecundity "response".

3) Jaimehlers says the creationists are wrong on both counts. Jaimehlers says that neutral mutations are more common than harmful mutations, and carrying those neutral mutations eventually allows for complexity to develop.

4) I disagree with Jaimehlers that neutral mutations are more common. I've explained that it only looks like that because previous neutral mutations can persist for long periods. Whereas with new mutations the majority are deleterious. My rationale is that negative selection is constantly purging deleterious mutations (mainly by killing things or making them infertile), and when inherent population fecundity restores the population numbers the genes with good and neutral mutations are amplified.

5) I also say that building on neutral mutations is only one pathway to complexity - there are several more. Probably easier pathways are by gene duplication (then through random changes to the less conserved redundant gene copy), and accidental acquisition of large amounts of DNA from other species. (I'm not sure if Jaimehlers agrees with me on this, but he probably does because it's classic evolution theory.)

6) Jaimehlers has called me out to support my claim that bad mutations are more common. (I will do my best with this shortly.)

7) The reason I'm being so pedantic about all this is that creationists 'know' they are right about the destructive bias of random mutations, and the challenge in that for building complexity. Denying this does our case no favours - sure there are good examples of point mutations leading to novel function, but it's not very common. I say the better way to deflate the creationist bubble is to admit the limitations of mutation but understand the population dynamics (negative selection and fecundity) and all the other powerful mechanisms that do give rise to complexity, sometimes even relying on the destruction caused by mutations to whittle away the scaffold upon which complexity was built.

Theoretical is fine.Actually, let me ask you a question. How high do you think the rate of lethal mutations is? A ballpark estimate is fine.

Rather than me doing a mildly educated guess, here is some evidence from greater experts than I'll ever be:

Quote

One of the earliest theoretical studies of the distribution of fitness effects was done by Motoo Kimura, an influential theoretical population geneticist. His neutral theory of molecular evolution proposes that most novel mutations will be highly deleterious, with a small fraction being neutral. Hiroshi Akashi more recently proposed a bimodal model for DFE, with modes centered around highly deleterious and neutral mutations. Both theories agree that the vast majority of novel mutations are neutral or deleterious and that advantageous mutations are rare, which has been supported by experimental results. One example is a study done on the distribution of fitness effects of random mutations in vesicular stomatitis virus. Out of all mutations, 39.6% were lethal, 31.2% were non-lethal deleterious, and 27.1% were neutral.

Because more DNA changes are harmful than are beneficial, negative selection plays an important role in maintaining the long-term stability of biological structures by removing deleterious mutations. Thus, negative selection is sometimes also called purifying selection or background selection.

One study on the comparison of genes between different species of Drosophila suggests that if a mutation does change a protein, this will probably be harmful, with an estimated 70 percent of amino acid polymorphisms having damaging effects, and the remainder being either neutral or weakly beneficial

Our analysis suggests that approximately 95% of all nonsynonymous mutations that could contribute to polymorphism or divergence are deleterious, and that the average proportion of deleterious amino acid polymorphisms in samples is approximately 70%.

So the findings in different species and study methodologies confirm what I’m saying about most mutations being harmful. Of course many factors impact these studies and not all results can be perfectly adjusted for them. Dominant lethals, by their lethal nature, just don’t present themselves for study. Recessive lethals get purged in bottlenecks or bouts of local inbreeding. Some deleterious mutations can “surf” to higher frequencies on local waves of fecundity. Some are held in relatively stable polymorphisms by competing pressures e.g. the famous sickle cell anaemia example you quoted.

But the key to understanding the problem of damage caused by point mutations is that many genes make proteins (or regulate them). Proteins are not genetic information – they are 3D products that need to operate in a 3D molecular environment in which they’ve already adapted over many generations through natural selection. So structural proteins are quite sensitive to amino acid substitutions that alter their 3D structure, and in enzymes the 3D structure is particularly critical to catalytic function. It’s easier to stuff up the optimised 3D fit of folded proteins than it is to have changes with no effect or enhancements. But negative selection works steadily to cleanse the problems .

Quote

Furthermore, mutating an amino acid to a residue with significantly different properties could affect the folding and/or activity of the protein. There is therefore usually strong selective pressure to remove such mutations quickly from a population.